Tractor mounted tong loader



' J. B. CODLIN TRACTOR MOUNTED TONG LOI tDER 7 May 12, 1959 .J v FiledJuly 15; 1957 I )"lm h.

INVENTOR:

ATTORNEYS.

United States Patent 2,886,194 TRACTOR MOUNTED TONG LOADER James B.Codlin, Lake Blulf, Ill., assignor to Tractomotive Corporation,Deerfield, 111., a corporation of Illinois Application July 15, 1957,Serial No. 672,000

Claims. (Cl. 214-147) This invention relates to a tractor mounted tongloader and more particularly to a loader for handling logs and the like.

Tong loaders for logs have heretofore been proposed in which fork armsare provided for receiving a load of logs and pivoted tong arms aremounted to swing toward and away from the fork arms for gripping thelogs. In one type of construction a single tong arm has been pro- .videdin the form of a U-shaped member pivoted on its ends to the loader framewith its center portion swingable toward the fork arms to grip the load.If the loadis uneven, as is common with logs due to the taper thereof,the

logs may be gripped only at one side which results in a very unsafecondition or if sufficient pressure is applied to grip the load at bothsides the tong arms will be twisted and will eventually fatigue andbreak.

It has also been proposed to utilize two independently movable tong armsto grip the logs at spaced points. Loaders of this type are generallysatisfactory, but in picking up relatively small logs from a pile, as inhandling pulp wood, it has been found that occasionally one .tong willengage one log and the other tong will engage "a different log. When theload is raised the logs cross and swing around in the loader or may flyloose again resulting in a dangerous condition.

It is one of the objects of the present invention to provide a tractormounted tong loader in which independently movable tong arms areconnected through lost motion means to limit relative movement thereofso that they normally function together, but can have a limited amountof relative movement to grip an uneven load uniformly.

Another object is to provide a loader in which the tong arms curvetoward each other and are connected at their free ends for limitedrelative swinging movement.

According to a feature of the invention, one of the tongarms is formedwith a notch at an angle to a radius from its pivotal axis and the otherarm is formed with a tongue fitting loosely in the notch to limitrelative movement between the arms.

A further object is to provide a loader in which the forks are pivotallyconnected to the supporting frame and engage the frame to limit pivotalmovement thereof in one direction while remaining free to pivot in theother 5 direction.

i-The above and other objects and features of the invention will be morereadily apparent from the following description when read in connectionwith the accompanying drawing, in which:

Figure l is a perspective view of a tractor mounted tong loaderembodying the invention;

Figure 2 is a side elevation of the loader;

Figure 3 is a partial rear elevation in the plane 3-3 of Figure 2; and

Figure 4 is a partial perspective view of the ends of the tong armslooking from the front in Figure 1.

The loader of the present invention is adapted to be mounted on atractor of any desired type, as shown generally at 10, which is movableon tracks 11 or on Wheels to difierent places to pick up and discharge aload of logs, or the like. For mounting the loader the tractor haspivotally mounted thereon forwardly extending booms 12 and a controllinkage for controlling tilting of the loader. The control linkage, asshown, comprises links 13 generally parallel to the booms 12 andpivotally connected at their upper ends to vertically extending crosslinks 14 which are pivoted at their lower ends to the booms 12. Thecross links are connected through expansible hydraulic motors 15 tofixed pivot points on the tractor frame so that when the motors 15 areexpanded or contracted a supporting frame carried by the linkage'will betilted about a horzontal axis. The precise linkage as shown does not,per se, form a part of the present invention and is illustrated asconstructed in accordance with the patent to Dobeus, No. 2,685,973.

The loader is adapted to be secured to the linkage to be elevatedthereby as the linkage is swung in a vertical plane and to be tiltedabout a horizontal axis for loading and unloading operations. Thesupporting frame, as shown, comprises a pair of side members 16 whichmay be of generally channel section and which extend vertically upwardfor substantially one-half their length and then angle forwardly asshown. Theside members 16 are connected by an upper cross bar 17 and alower cross framework 18 which, as shown in Figure 2, includes a crossbeam 19 extending across the lower part of the framework and close tothe forward edge portion of the side members 16. The framework ismounted on the linkage by pivotally connecting the booms 12 to the lowerpart thereof at opposite sides on pivotal axes 21 and by connecting theupper control links to the side members 16 above the bottoms thereof onpivotal axes 22. With this connection, when the booms are raised by theusual mechanisms provided on the tractor the supporting frame will beelevated without substantial tilting movement and when the hydraulicmotors 15 are expanded the frame will be tilted forwardly for unloading,as described hereinafter. 3

The frame carries a pair of spaced forwardly extending fork memberswhich are formed by angular beam elements 23 with the lower arms 24thereof extending approximately horizontally forward from the lower partof the frame. The upper ends of the upper arms of the fork elements arepivoted to the side members 16 on pivotal axes 25 and extend downwardlytherefrom to engage the cross beam 19 so that swinging of the forkmembers in a counter-clockwise direction, as seen in Figure 2, islimited while leaving the fork members free to swing in a clock wisedirection. The horizontal and vertical arms of the fork members areconnected with fillet plates 26 which strengthen the fork members andwhich provide a curved surface for the reception of the load of logs, orthe like.

Logs received on the fork members are adapted to be gripped and heldthereon by tong arms 27 and 28. The tong arms, as shown, are ofcomplementary shape and-are pivoted on coaxial pivots 29 at the upperends of the vertical members 16, respectively. Below the pivots 29 thetong arms curve outwardly as seen in Figure 2 and simultaneously towardeach other, as best seen in Figure 1, so that their free ends are closetogether. For moving the tong arms hydraulic motors 31 are provided inthe supporting frame with one end of each motor being pivotallyconnected to one of the Vertical members 16 on an axis 32 and with itsopposite end being pivotally connected to an extension 33 projectingbeyond the pivotal axis 29 of the tong arm. The motors 31 may besupplied with operating fluid from a common source so that they willexert equal pressure on a load and so that they are capable ofindependent movement, as more particularly disclosed in the patent toCarlson, No. 2,776,768. With this construction, when the motors 31 arecontracted the tong arms will swing clockwise, as seen in Figure 2, tomove away from the lower tong arms 24 for reception of a load of logs.When the motors are expanded, the arms will be swung counter-clockwisetoward the fork arms 24 to grip the logs thereon. Preferablythe tongarms are capable of swinging to substantially the maximum closedposition shown in Figure 2 so that they will grip and hold a relativelysmall number of logs on the fork arms for handling a partial load.

According to the present invention, the free ends of the fork arms 27and 28 are connected through lost motion connection means for a limitedamount of swinging movement relative to each other. For this purpose, asbest seen in Figure 4, the tong arm 27 is formed with an enlarged endprovided with a notch 34 and the tong arm 28 is provided with a tongue35 fitting loosely in the notch 34 when the arms are assembled on thesupporting framework. As shown by the dotted lines in Figure 2, thegroove 34 and tongue 35 lie at an acute angle to a radius therethroughfrom the pivotal axis 29 so that after a limited amount of relativemovement of the arms the tongue 35 will engage one side or the other ofthe notch or groove 34 to limit relative swinging of the tong arms.

In use, the tong arms may be raised away from the lower fork arms 24 sothat longs may enter freely over the ends of the fork arms to besupported thereby. In this operation the fork arms are normally loweredonto the ground or onto the side of a pile of logs and the tractor isadvanced toward the logs so that the fork arms will slide under them.The pivotal mounting of the fork arms on the supporting frame enablesthem to move independently of each other during this operation toaccommodate irregularities in the ground or in the surface over whichthey are moved so that the frame or the supporting linkage will not bestrained or bent. When the fork arms have been moved under a load oflogs the tong arms are swung downwardly by operation of the hydraulicmotors 31 to grip the logs so that they may be picked up andtransported.

Normally the fork arms move together as a single unit so that there isno possibility of the different fork arms engaging different logs. Asthe fork arms move into gripping position and in the event the load isthicker at one side of the unit than at the other, the fork arms maymove independently to each other to a limited extent so that each forkarm will securely grip the load at opposite sides thereof. Normally arelatively small amount of movement between the fork arms will besufficient to insure uniform gripping and the lost motion connectionprovided by the groove 34 and tongue 35 may be made sufficient toaccommodate all of the conditions normally encountered.

With the logs gripped, the frame may be tipped back if desired bycontracting the hydraulic motors 15 to bring the center of gravity ofthe load closer to the tractor and may then be raised to a carryingposition above the ground. For unloading on a truck, or the like, thesupporting frame may be raised to a suflicient elevation to clear thesides of the truck and any previous load thereon and the hydraulicmotors 15 may be expanded to tilt the supporting frame forward. When thetong arms 27 and 28 are elevated the logs carried on the fork arms 24will roll from the forward end thereof to the desired loaded location.

While one embodiment of the invention has been shown and describedherein, it will be understood that it is illustrative only and not to betaken as a definitionof the scope of the invention, reference being hadfor this purpose to the appended claims.

What is claimed is:

1. A tractor mounted tong loader comprising a frame, means to mount theframe on a tractor for bodily swinging in a vertical plane and fortilting about a horizontal axis, spaced forks carried by the frame andprojecting outward therefrom at the lower part thereof to receive a loadof logs or the like, a pair of tong arms separately pivoted on ahorizontal axis on the upper part of the frame at horizontally spacedpoints and curving toward each other, lost motion means connecting thefree ends of the tong arms to limit relative pivotal movement thereofabout said axis to a predetermined amount, and a pair of motor meansconnected to the frame and the tong arms respectively to swing the tongarms about the horizontal axis.

2. The loader of claim 1 in which the motor means comprises a pair offluid motors connected to the tong arms respectively.

3. A tractor mounted tong loader comprising a frame, means to mount theframe on a tractor for bodily swinging in a vertical plane and fortilting about a horizontal axis, spaced forks carried by the frame andprojecting outward therefrom at the lower part thereof to receive a loadof logs or the like, a pair of tong arms pivoted on a horizontal axis onthe upper part of the frame at horizontally spaced points and curvingtoward each other, the free ends of the tong arms being formedrespectively with a notch at an angle to a radius from the pivotal axisof the arms and a tongue fitting loosely in the notch to limit relativemovement of the tong arms, and means to swing the tong arms about theirpivotal axis.

4. The loader of claim 3 in which the last named means comprises a pairof fluid motors connected to the tong arms respectively.

5. A tractor mounted tong loader comprising a vertically elongatedframe, means mounting the frame on a tractor for bodily swinging in avertical plane and for tilting about a horizontal axis, a pair ofangular fork arms pivotally mounted at opposite sides of the frame on ahorizontal axis above the bottom of the frame, the fork arms extendingdownward and engaging the frame below their pivotal axis to limitpivotal movement thereof in one direction and projecting outward fromthe frame at the lower part thereof to receive a load, a pair of tongarms pivoted on a horizontal axis on the upper part of the frame on ahorizontal axis at horizontally spaced points and curving toward eachother, the free ends of the tong arms being formed respectively with anotch at an angle to a radius from the pivotal axis of the arms and atongue fitting loosely in the notch, and a pair of fluid motorsconnected to the tong arms respectively to swing them about theirpivotal axis.

References Cited in the file of this patent UNITED STATES PATENTS1,953,926 Cammen Apr. 10, 19 34 2,418,251 DI'Ofl; Apr. 1, 1947 2,776,768Carlson Jan. 8, 1 957

